How to properly clean a mouthguard (e.g., a nightguard)?

How to properly clean a mouthguard (e.g., a nightguard)?

For example, https://mouthguardsforteethgrinding.com/how-to-clean-your-mouth-guard-effectively/ (mirror) mentions 7 general methods:

• Toothbrush and toothpaste
• Mouth Rinse
• Soap and Water
• Mouth guard cleaning tablets
• Dental sanitizing devices
• Natural cleaning methods

Are the equally efficient?

For example, I have read on https://riverrundentalspa.com/instructions-for-cleaning-your-night-guard/ (mirror) that the use of toothpaste is deleterious to the mouthguard:

You don’t need to apply toothpaste to the brush. Since toothpaste can be abrasive, it may scratch your night guard and cause it to wear out more quickly.